Ashoka Conquers Kalinga and Turns to Buddhism
The sight of a battlefield strewn with the dead drives an emperor to renounce the wars that built his empire
Quick facts
- War
- Conquest of Kalinga, c. 261 BCE
- Casualties per Ashoka's edicts
- 100,000 killed, 150,000 deported
- Result
- Ashoka's conversion to Buddhism and adoption of dhamma policy
- Primary source
- Ashoka's own rock and pillar edicts
What happened
About eight years into his reign, the Mauryan emperor Ashoka invaded Kalinga, a coastal kingdom in what is now the Indian state of Odisha, in a war that killed more than 100,000 soldiers and civilians and left another 150,000 deported. Ashoka's own edicts describe his reaction: walking the battlefield afterward, he stated that he felt deep remorse at the slaughter, deportation, and death that conquest of an unsubjugated people necessarily brings. In the years that followed he adopted Buddhism and, according to his inscriptions, committed to ruling through dhamma, a policy of moral conduct and nonviolence, rather than continued military expansion. He would go on to describe conquest by dhamma as the only conquest worth pursuing, urging his descendants toward restraint even if future wars proved necessary.
Why it matters
Ashoka's conversion turned the most powerful ruler in South Asia into an active patron of Buddhism, a shift that helped transform Buddhism from a regional movement into a religion that spread across and beyond the subcontinent. It is also one of the clearest cases in ancient history of a ruler's own words, carved in stone, directly describing his change of conscience rather than having it inferred from later legend.
How we know
Ashoka's own edicts, inscribed on rock faces and stone pillars across his empire, are the primary source for both the Kalinga war's casualty figures and his stated remorse, making this one of the best directly self-documented events in ancient Indian history.
Sources
- World History (Lumen Learning course, drawing on Boundless World History). Ashoka's Conversion · General sourcecourses.lumenlearning.com · Cited as a "reference" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
- World History Encyclopedia (text of Ashoka's edicts). The Edicts of Ashoka the Great · Primary source (author-declared)worldhistory.org · Cited as a "primary" source (no stronger domain match). · Link is live and its text matches the event's key terms (Jul 2026)
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